贵州省瓮福磷矿穿岩洞矿段矿石地球化学特征

Geochemical Characteristics of Ores in Chuanyandong Ore Block of Wengfu Phosphate Mine,Guizhou Province

瓮福磷矿是贵州省重要磷矿区,是“瓮福式”磷矿的代表矿床,其中穿岩洞矿段发挥了重要作用。以穿岩洞矿段基础地质特征及地球化学特征为研究方向,通过对主量、微量及稀土元素等的分析,阐明了穿岩洞矿段磷块岩以碳氟磷灰石为主,矿石类型主要为条纹条带状砂屑磷块岩、生物颗粒屑磷块岩等。矿石P_(2)O_(5)含量较高,普遍高于全国磷矿石平均品位。As、Cr、Ni、Pb、Rb、Sr、U、V、Zr等微量元素含量较高。U/Th、Co/Ni等比值特点反映出沉积过程中收到热水沉积影响,稀土元素配分型式为右倾型,具有较为显著的Ce、Eu负异常,表明磷块岩形成于氧化环境。

Wengfu Phosphate Mine is an important phosphate mining area in Guizhou Province,and is the representative deposit of"Wengfu type"phosphate mine,in which the Chuanyandong ore section plays an important role.This study focuses on the basic geological and geochemical characteristics of the Chuanyandong ore block.Through the analysis of major elements,trace elements and rare earth elements,it is clarified that the phosphorite in the Chuanyandong ore block is mainly carbon fluorine apatite,and the ore type is mainly striped and banded psammitic phosphorite,biological particle clastic phosphorite,etc.The P_(2)O_(5) content of the ore is high,which is generally higher than the average grade of phosphate rock in China.The contents of As,Cr,Ni,Pb,Rb,Sr,U,V and Zr are higher.U/Th,Co/Ni and other ratios show that the depositional process was influenced by the hydrothermal sediments.The REE distribution pattern is right-inclined type with obvious negative Ce and Eu anomalies,indicating that the phosphorite was formed in an oxidizing environment.